1. Acids donate H+ ions in solution while bases accept H+ ions, helping to regulate pH. 2. The bicarbonate buffer system, hemoglobin buffer system, and phosphate buffers help maintain acid-base balance by absorbing excess H+ ions. 3. Imbalances can occur from respiratory or metabolic causes and are diagnosed based on blood pH and bicarbonate levels, with treatment focusing on the underlying condition and restoring normal acid-base levels.

1. Thara Noel
MSc (N) Medical
Surgical Nursing

2. ACIDS &BASES
Acid
Any compound which can give up a H⁺ ion
in solution (proton donors)
e.g. Carbonic acid releases H⁺ ions to
form bicarbonate(HCO3-)•
Base
Any compound which can accept a H⁺ ion
in solution (proton acceptors)
eg:Bicarbonate(HCO3⁻) accepts H+ ions
to form carbonic acid(H2CO3- )

4.  Acidosis- Physiological state resulting
from abnormally low plasma pH
 Alkalosis- Physiological state resulting
from abnormally high plasma pH
 Acidemia: plasma pH < 7.35
 Alkalemia: plasma pH > 7.45

6. REGULATION OF ACID-BASE
BALANCE
 Bicarbonate buffers
 Hemoglobin buffering system
 Phosphate buffers
 Bone buffers

7. BICARBONATE BUFFER SYSTEM
 The body cells constantly generate
carbon dioxide
 Most carbondioxide,a by-product of
cellular metabolism, is dissolved in the
blood and converted to carbonic acid.
 Most of the carbonic acid then
dissociates to bicarbonate and
hydrogen ions.

8. BICARBONATE BUFFER
SYSTEM

9. HEMOGLOBIN BUFFER
SYSTEM
 CO2 diffuses across RBC membrane
 Bicarbonate ions diffuse into plasma
in exchange for chloride ions (chloride
shift)
 Hydrogen ions are buffered by
hemoglobin molecules.
 Helps prevent major changes in pH
when plasma PCO2 is rising or falling
Phosphate Buffer System

10. HEMOGLOBIN BUFFER
SYSTEM

14. ROLE OF LUNG AND KIDNEY IN
ACID-BASE BALANCE

17. ACID BASE
IMBALANCES

20. CAUSES
AIRWAY
OBSTRUCTION
PULMONARY
SYSTEMIC
NEURO
MUSCULAR
CNS
METABOLIC

21. CLINICAL FEATURES
 Dyspnoea,Tachypnoea
 Restlessness, Confusion
 Diaphoresis,Lathargy
 Cyanosis
 Dilated Conjunctival and facial blood
vessel
 Ventricular dysrrhythmias
 coma

23. TREATMENT
 Treat underlying cause
 Oxygen supplement
 CPT,Postural drainage
 Suctioning
 Intubation and mechanical ventilation
 Deep breathing exercise
 Antibiotics,Bronchodialators

25. CAUSES OF RESPIRATORY
ALKALOSIS
 Direct stimulation of respiratory centre
 Anxiety,Fear,Pain
 Salicylates(stimulate respiratory center)
 Mechanical hyperventilation
 Intracerebral trauma
 Gram negative sepsis
 Pregnancy
 Hepatic insufficiency

26. CLINICAL MANIFESTATIONS
 Anxiety
 Light headedness
 Paresthesia
 Circumoral numbness
 Confusion
 Arrhythmias
 Tetany, Syncope
 Seizures

27. MANAGEMENT OF
RESPIRATORYALKALOSIS
.
• Treat Underlying cause
• Sedatives and tranquilizers
.
• Rebreath into paper bag
• Pulsoxymetry
.
• Pain management
• Decrease ventilation(Rate, VT)

28. METABOLIC ACIDOSIS
 Metabolic
acidosis is defined
as a pH less
than7.35 with
HCo3 less than22
meq/L
 Excessive acid loss  Bicarbonate
retention

29. CAUSES OF METABOLIC
ACIDOSIS
 Loss of Bicarbonate
 Excess acid production
 Excess acid ingestion
 Inability of the kidney to excrete
ion load

31. MANAGEMENT
 Treat underlying cause
 In DKA, Fluids and Insulin
 For CRF Hemodialysis, Peritoneal
dialysis.
 Oral bicarbonate ,IV Sodium
bicarbonate(2 to 5 mEq/kg IV infusion
over 4 to 8 hours; subsequent doses
should be based on patient's acid-base
status)

33. CAUSES OF METABOLIC
ALKALOSIS
 Vomiting, Nasogastric suctioning
 Diuretics(Loop diuretics,Thiazide
diuretics)
 Mineralo corticoids
 Hyper calcemia,Hypo parathyroidism
 Hypokalemia
 CHO Refeeding after starvation

34. Cont…..
 Administration or Ingestion of
Bicarbonate
 Massive blood transfusion
 Diuretics
 Cystic fibrosis

35. MANAGEMENT
 Treat underlying cause
 Treat hypokalemia with oral or IV
Potassium salts
 Isotonic saline infusion to correct volume
deficits
 Azetazolamide in congestive heart
failure